x1,y1,x2,y2=map(float,input().split())
n=((x1-x2)**2+(y1-y2)**2)**(1/2)
print('{:.8f}'.format(n)) x1,y1,x2,y2=map(float,input().split()) x1 map(float,input().split()) map float input().split() ().split () input split y1 x2 y2 n=((x1-x2)**2+(y1-y2)**2)**(1/2) n ((x1-x2)**2+(y1-y2)**2)**(1/2) (x1-x2)**2+(y1-y2)**2 (x1-x2)**2 x1-x2 x1 x2 2 (y1-y2)**2 y1-y2 y1 y2 2 1/2 1 2 print('{:.8f}'.format(n)) print '{:.8f}'.format(n) '{:.8f}'.format '{:.8f}' format n y1,x2,y2=map(float,input().split()) map(float,input().split()) y1 n=((x1-x2)**2+(y1-y2)**2)**(1/2) ((x1-x2)**2+(y1-y2)**2)**(1/2) n x2,y2=map(float,input().split()) map(float,input().split()) x2 x1,y1,x2,y2=map(float,input().split()) map(float,input().split()) x1 y2=map(float,input().split()) map(float,input().split()) y2
x1,y1,x2,y2=map(float,input().split())
n=((x1-x2)**2+(y1-y2)**2)**(1/2)
print('{:.8f}'.format(n))
